The present invention relates to a system and a method for detecting obstacles in a forward path, especially to a path detection system and a path detection method generating laser patterns by a diffractive optical element (DOE), in which structured light of the laser pattern projected by a laser light source through the DOE is used for detection. The structured light includes a transverse baseline and at least one transverse computational line.
The system and the method for detecting obstacles in a forward path according to the present invention are applied to a mobile device while in use. The mobile device is defined as, but not limited to, a robot able to move or a machine that moves automatically. For example, take a common room/clean robot as an example. When the room/clean robot without a system for obstacle detection in a forward path is used indoors, the room/clean robot is moved right forward when there is no obstacle in the forward path. The room/clean robot changes the direction of the motion randomly when it bumps into an obstacle. As to some other room/clean robots with ultrasonic detection system, they have shortcomings of inaccurate detection signals and lack of precision, false results, etc. Thus the conventional room/clean robot is unable to detect and avoid the obstacles in the forward path efficiently. The room/clean robot is also unable to have path planning ability. Thus the working efficiency of the conventional room/clean robot is lowered.
Moreover, although the use of the structured light in detection and location of obstacles has been revealed in some papers, these prior arts get problems of sophisticated system structure, difficulty in miniaturization, etc. in applications. Thus the efficiency of the device is low and this has negative effect on introduction of the device into various mobile devices.
Furthermore, there are already many prior arts available now in the field of a virtual input device (virtual keyboard) formed by projection techniques such as U.S. Pat. No. 6,614,422, US2012/0162077, US2014/0055364, etc. A system and a method using a virtual input device such as virtual keyboard or virtual mouse to input data are revealed. Although the above prior art already discloses how to detect and locate an operating element (such as user's finger) on a button of a virtual keyboard. Yet such technique is different from the detection system and method of the present invention able to be installed on a mobile device while in use. The technique is unable to be directly applied to various kinds of mobile devices.
In addition, refer to U.S. Pat. Nos. 7,348,963, 7,433,024, US2008/0240502, US 2008/0106746, US 2009/0185274, US 2009/0096783, US 2009/0034649, US 2009/0185274, US 2009/0183125, and US 2010/0020078, a remote-control user interface uses a featured object (control member) such as gesture or a part of human body that changes in relative positions and actions in a three-dimensional space (X, Y, Z coordinates) for remote control of various functions of a display. But the technique mentioned above is still different from the detection system and method of the present invention. Thus the system of the remote-control user interface is unable to be directly applied to various kinds of mobile devices.